SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '40348795147cb1e08a7b4e3477fcb99b8d8c3174b7851ec9a754e0915c6e5050' 
  AND token = '3WjQIMAdv7qTZx6EVoDzym21eWg04/j2xqI5dgLTkWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}